In general, penis, the male sexual contact organ can be divided into three parts, penile muscle, penile body and glans.
Penis is an erectile tissue comprising two penile spongy bodies, one urethral spongy body, and a glans which is the expanded part of the front of the urethral spongy body.
In the inner wall of these spongy bodies, there are many pillars composed of connective tissues and smooth muscles intersecting each other to form a net shape, whose structure is similar to that of a sponge because a great number of small spaces such as penile spongy body blocks and urethral spongy body blocks are formed by these intersections. These spongy body blocks, which are a kind of vertical arteria are connected to each other, and are always filled with blood because arteria flows in and vena flows out through spongy body blocks.
When the blood vessels of these spongy body blocks are blocked or narrowed by any reason, normal blood flow movement is interrupted.
Therefore, recently, a hand-operated appliance is being developed in order to overcome such disadvantage; however, because the appliance must be operated by the user manually it does not have any remarkable effect.